Kathrein MSK 24 manual Technical Appendix, Signal-to-noise distance, +14.1 dB

Technical Appendix

Signal-to-noise distance

The following values must be known in order to calculate the carrier-to- noise distance (C/N) for analogue transponders.

∙background noise level (set parabola antenna so that no satellite signal is received)

∙max. receiving level

∙bandwidth correction.

This gives the following formula:

C/N = receiving signal level - background noise level - bandwidth correction

Measured bandwidth of MSK 24 6 MHz

Bandwidth correction value = 10 log ——————————————–--------

RF bandwidth of receiving signal

Bandwidth correction value = 6.37 dB at 26 MHz bandwidth (Astra)

Bandwidth correction value = 7.78 dB at 36 MHz (Eutelsat, Intelsat, Kopernikus)

Example
	Receiving signal level	+75.5 dB	with satellite signal
0	Background noise level	-55.0 dB	without satellite signal
	Carrier-to-noise distance C/N	+20.5 dB
	Bandwidth correction	- 6.4 dB	for 26 MHz bandwidth
	C/N of the receiving system	+14.1 dB

Note

+	To calculate C/N exactly, it is essential that you take the RF bandwidth of
	the receiving signal into account.

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